With the increasing of user requirements for wireless multimedia services, limited wireless resources are becoming more and more insufficient, which promotes the fast development of the communication technologies on efficient utilization of the wireless resources. The birth of 3G, B3G, and 4G standards brings along the proposals of various advanced wireless techniques, which makes the spectrum efficiency per link approach a theoretical limit. In such a case, the study of resource utilization turns to the increasing of the spectrum efficiency per area unit. Thus the network planning in system level is becoming more and more important.
For example, LTE Advanced standard introduces a heterogeneous network which includes a macro base station, a micro base station, a femto base station and a relay base station, and the like. Such a hybrid networking manner is flexible, convenient and economic, and ensures the wireless users to obtain a consistent user experience wherever they are. Moreover, an organization or person may establish various wireless networks as required, in addition to communication networks, which increases the complexity of the heterogeneous network.
The heterogeneous network has abundant meaning in various aspects such as wireless techniques, coverage ranges, network architecture and network performance; and forms a three-dimensional geographic coverage. On one hand, the increasing of number of infrastructure nodes in the network topology may shorten the distance of the user access links, improve the link quality and thus increase the network capacity. On the other hand, the addition of relay stations which performs the forwarding function may result in the repeated data transmission and thus reduce the effective data rate in the network.
To improve the effective data rate in the heterogeneous network, network coding technique is introduced in the heterogeneous network, which may improve both the system capacity and the effective data rate via multi-point coordination.
The network coding technique may be a super set of routing techniques, which allows for the coding and combination of the information from different links. The network node can perform both the routing function and the coding function so that the network approaches the limit of maximum stream transmission.
In the scenario of the heterogeneous network, since some of the infrastructure in heterogeneous network is mobile, the employed wireless technique may be reconfigured according to the application environment and the user distribution and bandwidth requirements change dynamically during the network operation. In this case, the management of network coding is becoming important.